摘要
Tip leakage flow affects the flow stability of high-loading compressors significantly.Therefore,a novel approach via induced shock wave near suction-side edge of blade tip was proposed to suppress the strength and influence range of leakage flow in a transonic rotor.Three new schemes with different circumferentially diverging degrees of clearance were designed to reveal the mechanism of the new approach.Through the action of the circumferentially diverging clearance(from the pressure side to the suction side over blade tip),a much more dramatic acceleration of the supersonic leakage jet flow appeared over blade tip of the new schemes.An induced shock wave was produced near the suction side edge of blade tip due to the pressure difference between the discharging leakage flow and the surrounding high-pressure mainflow in tip channel.As a result,both the mass flow rate and the outlet velocity of leakage flow were reduced significantly via the induced shock wave.Meanwhile,the suppressing effect of the new approach on the tip leakage jet flow was closely related to the strength and circumferential location of the induced shock wave.With the aids of the induced shock wave,the largest improvement of tip flow characteristics with an over 5%increase in stall margin was realized in new transonic rotor when the circumferential divergence angle equals 8°,accompanied with no more than a 0.4%decrease in isentropic efficiency.
基金
sponsored by the General Program of National Natural Science Foundation of China (Grant No.52076124)
the National Science and Technology Major Project (Grant No.J2019-Ⅱ-0014-0035)
